Finding the Fourth Proportional to 15,139.50, 20,892.18 and 8,424.72

Step by Step Solution

1. Step 1: Write the proportion equation
   15,139.50 : 20,892.18 = 8,424.72 : x
2. Step 2: Convert to fraction form
   15,139.50/20,892.18 = 8,424.72/x
3. Step 3: Cross multiply
   15,139.50x = 20,892.18 × 8,424.72
4. Step 4: Simplify right side
   15,139.50x = 176,010,798.28
5. Step 5: Solve for x
   x = 176,010,798.28/15,139.50
6. Step 6: Final answer
   x = 11,625.93